In certain yarn or other textile manufacturing processes, multi-filament yarns may undergo one or more internal binding, knotting, and/or tangling processes to produce yarns having desirable yarn characteristics, such as tensile strength, thickness, intermingling, intra-yarn cohesion, and/or the like. As just one example, interlacing (also known as tangling, entangling, and intermingling) serves to tangle the multiple filaments of a yarn along the length of the yarn to provide intra-yarn cohesion between the various filaments that collectively form the yarn.
In the interlacing process, a continuous, multi-filament yarn is directed along a yarn path at a defined tension. The yarn path passes through a tangling jet configured to direct a pressurized stream of air at the yarn from a direction that may be perpendicular or at an acute angle relative to the yarn's direction of travel along the yarn path. The pressurized air stream causes the filaments of the yarn to separate and then collapse together, thereby forming periodic tangled bundles of filaments (“nodes”) along the length of the yarn.
The relative size and positioning of the nodes may affect characteristics of the resulting yarn, and therefore various devices have been used to monitor the relative positions of the nodes along the length of yarns. However, historical attempts to monitor yarn interlacing characteristics have been subject to inconsistent and/or inaccurate accounting of interlacing characteristics. For example, natural variances in yarn thickness due to aspects of the yarn unrelated to interlacing and/or the relative size of loose nodes encompassing air pockets may result in inaccurate counting of nodes, and historical attempts to monitor interlacing characteristics have been unable to simultaneously monitor a plurality of interlacing characteristics such as node size, slack length (distance between nodes), and/or the like, of a particular yarn.
Accordingly, a need exists for a robust yarn characteristic monitoring device and method for monitoring a plurality of interlacing characteristics for continuous yarns.